The present invention relates to a charged particle exposure apparatus and a control method therefor and, more particularly, to a charted particle exposure apparatus having a plurality of control elements for controlling operation of drawing a pattern on a substrate with a charged particle beam and a control method therefor, an information processing apparatus for generating exposure control data to be supplied to the charged particle exposure apparatus and a control method therefor, and a device manufacturing method using a charged particle exposure apparatus controlled by this control method.
Examples of a charged particle exposure apparatus are an electron beam exposure apparatus and an ion beam exposure apparatus. The charged particle exposure apparatus is used for drawing a desired pattern on a substrate (e.g., a wafer or glass plate) for forming, e.g., a semiconductor integrated circuit, a mask or reticle used for manufacturing a semiconductor integrated circuit, or a display device such as an LCD.
The charged particle exposure apparatus scans a substrate with a charged particle beam while turning on/off a blanker that controls irradiation of the charged particle beam, thereby drawing a desired pattern on a resist on the substrate. Accordingly, the charged particle exposure apparatus requires a very large amount of exposure control data for controlling exposure performed by the charged particle beam.
FIG. 20 is a block diagram showing the schematic arrangement of a conventional charged particle exposure apparatus. For example, a storage 1101 is comprised of a hard disk device, and stores exposure control data for controlling exposure. The exposure control data is compressed and stored in the storage 1101 in order to reduce the data size. In exposure, necessary portions of a series of exposure control data are sequentially read out from the storage 1101 and are temporarily stored in a buffer memory 1102.
An expansion processor 1103 develops (expands) partial exposure control data temporarily stored in the buffer memory 1102, and supplies them to a correction processor 1104. The correction processor 1104 performs correction for decreasing the influence of a proximity effect, or corrects drift of the charged particle beam, and supplies corrected data to drivers 1105 to 1107.
A main body 1110 of the exposure apparatus has a blanker 1111 for controlling irradiation of the charged particle beam, a deflector 1112 for deflecting the charged particle beam, and a correction coil 1113 for correcting the focal position or aberration, all of which are driven by the drivers 1105 to 1107, respectively.
As described above, in general, the exposure control data are stored in the storage 1101 in the compressed state in order to decrease the data size. Even compressed, the data amount of the exposure control data is very large.
Therefore, a method of efficiently compressing exposure control data to be supplied to a charged particle exposure apparatus, without increasing the load of the charged particle exposure apparatus which uses the compressed exposure control data by expansion, is sought for.
The present invention has been made in view of the above situation, and has as its object to for example decrease the load of processing of a charged particle exposure apparatus when expanding exposure control data.
It is another object of the present invention to reduce the data size of exposure control data to be supplied to, e.g., a charged particle exposure apparatus.
According to the first aspect of the present invention, there is provided a charged particle exposure apparatus having a plurality of control elements for controlling operation of drawing a pattern on a substrate with a charged particle beam, comprising a storage for storing exposure control data including concatenated control data generated by concatenating and thereafter compressing at least two control data for respectively controlling at least two of the plurality of control elements within the same period, and a processor for reconstructing at least two control data by expanding the concatenated control data included in the exposure control data stored in the storage, and controlling at least two control elements in accordance with the two control data.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the exposure control data preferably includes a plurality of concatenated control data arranged in an order with which they are used for control.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, at least two control elements are preferably control elements of the same type.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the apparatus preferably further comprises a charged particle source for generating a plurality of charged particle beams, and the plurality of control elements preferably include a plurality of irradiation controllers for separately controlling whether the substrate is to be irradiated with the plurality of charged particle beams.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, each of the irradiation controllers preferably includes a blanker for controlling whether the charged particle beam is to be deflected.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the exposure control data preferably includes a plurality of concatenated control data, and each of the concatenated control data is preferably generated by concatenating and compressing at least two control data for respectively controlling at least two adjacent ones of the irradiation controllers.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the control data for controlling the irradiation controllers are preferably time series data generated by arranging information, indicating whether the charged particle beams are to irradiate, in an order with which they are used for control.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the concatenated control data is preferably generated by concatenating in series and compressing at least two of the control data serving as time series data.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the concatenated control data is preferably generated by concatenating in parallel and compressing at least two of the control data serving as time series data.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the plurality of control elements preferably include an irradiation controller for controlling whether the substrate is to be irradiated with the charged particle beam, a deflector for scanning the substrate with the charged particle beam, and a focus controller for controlling focus, and the concatenated control data is preferably generated by concatenating and compressing at least two of control data for controlling the irradiation controller, control data for controlling the deflector, and control data for controlling the focus controller.
In the charged particle exposure apparatus according to the first aspect of the present invention, for example, the apparatus preferably further comprises a data generator for generating the exposure control data on the basis of a pattern to be drawn on the substrate.
According to the second aspect of the present invention, there is provided a method of controlling a charged particle exposure apparatus having a plurality of control elements for controlling operation of drawing a pattern on a substrate with a charged particle beam, the method comprising the steps of reading out, from a storage, exposure control data including concatenated control data generated by concatenating and thereafter compressing at least two control data for respectively controlling at least two of the plurality of control elements within the same period, expanding the concatenated control data included in the read exposure control data, thereby reconstructing the at least two control data, and controlling the at least two control elements in accordance with the at least two control data reconstructed in the expanding step.
According to the third aspect of the present invention, there is provided an information processing apparatus for generating exposure control data to be supplied to a charged particle exposure apparatus having a plurality of control elements for drawing a pattern on a substrate with a charged particle beam, comprising a first data generator for generating concatenated control data by concatenating and compressing at least two control data for respectively controlling at least two of the plurality of control elements within the same period, and a second data generator for generating exposure control data including the concatenated control data.
According to the fourth aspect of the present invention, there is provided an information processing method of generating exposure control data to be supplied to a charged particle exposure apparatus having a plurality of control elements for drawing a pattern on a substrate with a charged particle beam, comprising the first data generating step of generating concatenated control data by concatenating and compressing at least two control data for respectively controlling at least two of the plurality of control elements within the same period, and the second data generating step of generating exposure control data including the concatenated control data.
According to the fifth aspect of the present invention, there is provided a memory medium for storing a control program that generates exposure control data to be supplied to a charged particle exposure apparatus having a plurality of control elements for drawing a pattern on a substrate with a charged particle beam, the control program including the first data generating step of generating concatenated control data by concatenating and compressing at least two control data for respectively controlling at least two of the plurality of control elements within the same period, and the second data generating step of generating exposure control data including the concatenated control data.
According to the sixth aspect of the present invention, there is provided a device manufacturing method comprising the step of drawing a pattern on a substrate while controlling a charged particle exposure apparatus in accordance with a control method according to the second aspect described above.
According to the seventh aspect of the present invention, there is provided a device manufacturing method using, in some of steps thereof, a charged particle exposure apparatus having a plurality of control elements for controlling operation of drawing a pattern on a substrate with a charged particle beam, the method serving to perform, with the charged particle exposure apparatus, the steps of reading out, from a storage, exposure control data including concatenated control data generated by concatenating and thereafter compressing at least two control data for respectively controlling at least two of the plurality of control elements within the same period, expanding the concatenated control data included in the read exposure control data, thereby reconstructing at least two control data, and drawing a pattern on the substrate while controlling at least two control elements and other control elements in accordance with at least two reconstructed control data and other control data.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.